1. Field of the Invention
The present invention relates to tape cassettes. More particularly, the present invention relates to an apparatus for use in a tape cassette cover which allows the cassette cover to be formed of a light reflective material.
2. Description of the Prior Art
Cassette tapes which are typically used with video cassette recorders have two tape reels which are mounted on hubs. A magnetic, opaque tape is coupled to the tape reels and is transferred from one reel to the other when the hubs turn during operation of the video cassette recorder.
Opposite ends of the tape usually include transparent tape leaders or trailers (hereinafter leader portions). The leader portions are used in combination with a tape end detector in the cassette recorder to accomplish detection of the end of the tape.
Typically, the tape end detector in the recorder includes a light source and two light detectors or photocells. When the tape cassette is inserted into the video cassette recorder, the light source enters the tape cassette through an aperture in the tape cassette cover which is positioned between the two tape reels. Also, the tape cassette cover has two windows located on opposite sides of the cover which are aligned with the photocells in the cassette recorder when the tape cassette is inserted into the recorder.
As the tape is wound from one tape reel to the other (for example, when the tape is being played or rewound) the tape follows a path which runs between the light source and the photocells. Since the tape is opaque (other than the transparent leader portions), the tape blocks light emitted from the light source, thereby keeping it from impinging on the photocells. However, when the tape is substantially unwound from one reel, one of the transparent leader portions of the tape is positioned in the tape path between the light source and a photocell. Therefore, when the tape is unwound, light from the light source passes through the transparent leader portion of the tape and impinges on the photocell. The photocell, in turn, emits an electrical signal which indicates that the tape is at its end and the recorder stops the hubs from turning.
Since the electrical signal which signifies that the tape is at an end is light activated, it is important to minimize any extraneous light in the cassette which could pass around the opaque tape and trigger the photocell at the wrong time. Basically, there are two sources of such extraneous light. The first is unwanted reflection from the light source itself and the second is extraneous light being transmitted through the base and cover from an external source of light. In the past, these extraneous light sources were minimized by packaging the tape in a light absorbent, black cassette cover.
Recently, many movies, sound recordings, educational programs and other programs have been prerecorded on cassettes which use tape end detectors of the type described above. These cassettes are commercially available to be purchased or rented at retail level outlets. Hence, retail marketing and advertising has become very important to companies who sell and rent the tapes.
Also, generally, in retail establishments which sell or rent the cassette tapes, the cassette tapes are openly displayed so that potential customers may review them. For this reason, it is desirable for the tape covers to be manufactured in various colors and styles which are aesthetically pleasing. However, until now, tape covers which were manufactured in light transmissive colors (i.e., colors besides black) would cause the cassette recorder to malfunction due to extraneous light being transmitted by reflection or by external sources in the cassette cover. This extraneous light would prematurely activate the photocells, thereby prematurely stopping the hubs from turning and the tape from being played, rewound, etc.
One attempt to address this problem is disclosed in a United Kingdom patent publication, in GB No. 2119751A. In the tape cassette shown in this reference, a tape cassette was made of a color other than black, but certain portions of the cassette were formed of black material or were coated black. However, this required the cassette to be specially painted or to be formed using a dual molding process.